Weve taken the M.U.L.E. and optimized it for even more comfort by including a NEW N.V.I.S. Back Panel that draws the pack away from a mountain bikers back. Hydrate for 3+ hours on the trail with a 100 oz OMEGA HydroTanium Reservoir. With superior secure overflow storage, and incredible stability, this is the hydration pack by which all others are judged.